This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SPECIFIC AIMS: 1. Identify novel and traditional renal disease risk factors for the progression of CKD (e.g. decline of GFR) in children 2. Characterize the impact of a decline in kidney function on neurodevelopment, cognitive abilities, and behavior. 3. Identify the prevalence and evolution of traditional and novel cardiovascular disease risk factors in progressive CKD. 4. Examine the effects of declining GFR on growth and the treatment of growth failure, and to assess the consequences of growth failure on morbidity in children with CKD.